Since America invented the automobile, you would think the world would have adopted American standards. Did the British always have cars with the steering wheel on the right?
Please, the motor car was first mass produced in the US, but it was created back in 1807 in France and then the first gasoline by a German, Herr Benz (yes, that one of Mercedes Benz fame) in 1865 or so with an engine development from Herr Daimler. Both were from the continent of Europe so they would have "driven on the right" although many early vehicles had central steering (see here) with something resembling the tiller of a boat which could be operated from either side (many early vehicles had a bench seat). The steering wheel appeared at the close of the 19th century, probably with a Panhard model adapted with a steering wheel the driver Vacheron in 1894. As it originally had a tiller, the steering wheel was probably in the center too (they weren't tilted yet, that came later in 1898).
With a proper steering wheel in front of the driver, the driver had to choose which side, and that followed the passing convention discussed for carriages that Quargy mentions is noted here and the convention of driving on the left apparently goes back to Roman times and was first formally noted in a British ordinance for crossing London Bridge in 1722. In 1736, the Germans introduced a national decree for crossing a new bridge over the Elbe on the right.
Robispierre's Administration after the revolution (1792-96) was responsible for a city wide ordinance for keeping to the right in Paris. Napoleon later spread this rule throughout his empire.
He didn't get to the UK, so they continued to drive on the left. He didn't get to several other countries too like Sweden but finally with the complications of switching sides at land borders continental Europe settled on the Right whilst the UK and Ireland settled on the left.
Just to be complicated, some early vehicles had the steering wheel on the kerb-side. This gave better visibility for avoiding pedestrians (and still happens for road cleaning vehicles). After traffic increases and the segregation of pedestrians and drivers, it seemed safer to move the driver towards the center of the road - so drive on the left, steering wheel on the right or vice versa.
For a more academic treatise see Ch6 "Power in the Road" in : Ways of the World: A History of the World's Roads and of the Vehicles That Used Them by M. G. Lay, James E. Vance Publ: Rutgers University Press, 1 Dec 1992
